Disclosed is a light guiding valve apparatus including an imaging directional backlight, an illuminator array and an observer tracking system arranged to achieve control of an array of illuminators which may provide a directional display to an observer over a wide lateral and longitudinal viewing range, wherein the luminous intensity of optical windows presented to the observer as viewing windows is controlled dependent on the lateral and longitudinal position or speed of an observer. Further an optical window control system may comprise detection of an observer's hand. An image control system may comprise a method to provide an image that can be switched from a first mode with a first brightness into a second mode with a high brightness region and low brightness region, where the brightness of the second low brightness region is matched to the first brightness.
Legal claims defining the scope of protection. Each claim is shown in both the original legal language and a plain English translation.
1. A directional backlight apparatus comprising: a directional backlight comprising a waveguide comprising first and second, opposed guide surfaces for guiding input light along the waveguide, and an array of light sources arranged to generate the input light at different input positions in a lateral direction across the waveguide, the waveguide further comprising a reflective end for reflecting the input light back through the waveguide, the second guide surface being arranged to deflect light after reflection from the reflective end as output light through the first guide surface, and the waveguide being arranged to direct the output light into optical windows in output directions that are distributed in the lateral direction in dependence on the input position of the input light; and a sensor system arranged to detect a position of a head of an observer; and a control system arranged to selectively operate a group of adjacent light sources to direct light into a corresponding group of adjacent optical windows, in a manner in which the identity of the light sources in the group varies, and for a given group of light sources the luminous flux of the light sources varies, in accordance with the detected position of the head of the observer.
A directional backlight system has a waveguide that guides light between two surfaces. An array of light sources injects light at different points along the waveguide's width. A reflective end bounces the light back. The second surface extracts and directs the reflected light through the first surface, creating optical windows. The direction of these windows depends on where the light was initially injected. A sensor tracks the observer's head position, and a controller activates groups of adjacent light sources, adjusting their brightness based on the head position. This steers the light towards the observer.
2. A directional backlight apparatus according to claim 1 , wherein the luminous flux of the light sources varies across a transitional range of the detected position of the head of the observer.
The directional backlight system from the previous description, which has a waveguide, light sources, a head-position sensor, and a controller that adjusts light source brightness based on head position to steer light towards the observer, smoothly changes the luminous flux (brightness) of the light sources as the observer's head moves within a transitional range. This avoids sudden jumps in brightness as the display tracks the user's viewing angle.
3. A directional backlight apparatus according to claim 2 , wherein a new light source is operated as a member of the group of adjacent light sources with a luminous flux that increases as the detected position of the head of the observer moves towards the output direction corresponding to the new light source.
Building on the previous directional backlight system description, where light source brightness smoothly varies with head position, when a new light source becomes part of an active group, its brightness increases gradually as the observer's head moves closer to the direction the light source is designed to illuminate. This gradual increase creates a smoother transition as the display steers the light to the user.
4. A directional backlight apparatus according to claim 3 , wherein a light source is operated at an end of the group of adjacent light sources opposite from the new light source with a luminous flux that decreases as the detected position of the head of the observer moves towards the output direction corresponding to the new light source.
Expanding on the directional backlight system with smooth light source transitions and gradual brightness increases for new light sources, a light source at the opposite end of the active group from the new, brightening light source dims as the observer's head moves towards the new light source's direction. This ensures that light is focused towards the observer and reduces stray light in other directions.
5. A directional backlight apparatus according to claim 2 , wherein, across ranges of the detected position of the head of the observer intermediate to the transitional ranges, the identity and luminous flux of the light sources in the group does not vary.
In the directional backlight system with transitional brightness changes, when the observer's head position is stable (not in a transitional area), the active group of light sources and their respective brightness levels remain constant. The light only shifts in response to head motion within the defined transitional ranges, and remains steady in the non-transitional ranges.
6. A directional backlight apparatus according to claim 1 , wherein the first guide surface is arranged to guide light by total internal reflection and the second guide surface comprises a plurality of light extraction features oriented to direct light guided through the waveguide in directions allowing exit through the first guide surface as the output light and intermediate regions between the light extraction features that are arranged to guide light through the waveguide.
In a directional backlight system, the first waveguide surface uses total internal reflection to guide light. The second surface has light extraction features and intermediate regions. These features redirect the guided light to exit through the first surface. The intermediate regions continue to guide light. This allows controlled light extraction for directional viewing.
7. A directional backlight apparatus according to claim 6 , wherein the second guide surface has a stepped shape comprising facets, that are said light extraction features, and the intermediate regions.
The directional backlight system, which uses a waveguide with light extraction features, features a second guide surface with a stepped shape. The steps act as the light extraction features, alternating with the intermediate regions that guide the light. The facets redirect the light.
8. A directional backlight apparatus according to claim 6 , wherein the light extraction features have positive optical power in the lateral direction.
In the directional backlight system with light extraction features, the extraction features (on the second waveguide surface) have positive optical power in the lateral (width) direction. This helps to focus or shape the extracted light, optimizing the viewing angle and brightness.
9. A directional backlight apparatus according to claim 1 , wherein the first guide surface is arranged to guide light by total internal reflection and the second guide surface is substantially planar and inclined at an angle to direct light in directions that break that total internal reflection for outputting light through the first guide surface, and a deflection element extending across the first guide surface of the waveguide is arranged to deflect light towards the normal to the first guide surface.
In the directional backlight system, the first guide surface uses total internal reflection, and the second guide surface is nearly flat but angled to disrupt this reflection. A deflection element on the first surface then redirects the light, directing it towards the viewer.
10. A directional backlight apparatus according to claim 1 , wherein the reflective end has positive optical power in the lateral direction.
The directional backlight system has a reflective end with positive optical power. The reflector focuses or shapes the light as it is reflected back through the waveguide, optimizing the directional output.
11. A display apparatus comprising: a backlight apparatus according to any claim 1 ; and a transmissive spatial light modulator arranged to receive the output light from the first guide surface of the waveguide and to modulate it to display an image.
A display apparatus uses the directional backlight system (waveguide, light source array, head tracking, and light steering) to illuminate a transmissive spatial light modulator. The modulator creates an image from the backlight, providing a directional display.
12. A display apparatus according to claim 11 , being an autostereoscopic display apparatus wherein the control system is further arranged to control the spatial light modulator to display temporally multiplexed left and right images and synchronously to selectively operate groups of adjacent light sources to direct the displayed left and right images into respective groups of adjacent optical windows in positions corresponding to left and right eyes of an observer.
The display apparatus from the previous description is an autostereoscopic (3D) display. The controller rapidly switches between left and right eye images on the spatial light modulator. Simultaneously, the backlight steers the left and right images' light to the corresponding eye positions, as determined by the head tracking system.
13. A directional display apparatus comprising: a directional display device capable of directing output light selectively into optical windows of a set of optical windows in output directions that are distributed across the display device; and a control system arranged to control the display device to direct the output light into at least one selected optical window of the set, the directional display apparatus being arranged to sense a disposition of a hand of an observer, the control system being arranged to change the control of the display device in response to the sensed disposition of the hand of the observer.
A directional display directs light into optical windows. A control system chooses which window(s) to illuminate. The display senses the position/gesture of a user's hand, and the control system adjusts the display's output (illuminated windows) in response.
14. A directional display apparatus according to claim 13 , wherein the control system is arranged to shift the at least one selected optical window across the set in response to the directional display apparatus sensing movement of the hand of the observer across the display device in the direction in which the output directions are distributed.
The directional display system which controls light output based on hand position, shifts the selected optical window as the user moves their hand across the display in the direction corresponding to the distribution of the optical windows.
15. A directional display apparatus according to claim 14 , wherein the control system is arranged to change the brightness of the at least one selected optical window in response to the directional display apparatus sensing movement of the hand of the observer across the display device in a direction perpendicular to the direction in which the output directions are distributed.
The directional display system that adjusts light output based on hand position, changes the brightness of the selected optical window based on hand movement perpendicular to the direction the optical windows are distributed.
16. A directional display apparatus according to claim 13 , wherein the control system is arranged to change the number of optical windows that are selected in response to the directional display apparatus sensing a change in separation of fingers of the hand of the observer.
The directional display system, where light output is controlled in response to hand gestures, changes the number of illuminated optical windows based on the separation between the user's fingers.
17. A directional display apparatus according to claim 13 , wherein the directional display device is a touch-sensitive directional display device that is arranged to sense the disposition of the hand of the observer in proximity to the directional display device.
In the directional display system that responds to hand gestures, the display is touch-sensitive, and senses the hand's position when it is close to the screen.
18. A directional display apparatus according to claim 13 , further comprising: an image sensor system arranged to sense the disposition of the hand of the observer.
The directional display system, which controls light output based on hand position, uses an image sensor to track the user's hand.
19. A directional display apparatus according to claim 13 , wherein the directional display device comprises: a directional backlight capable of directing output light selectively into said optical windows; and a transmissive spatial light modulator arranged to receive the output light from the directional backlight and to modulate it to display an image.
The directional display system, which directs light into optical windows and responds to hand gestures, uses a directional backlight to create the light and a transmissive spatial light modulator to form the image.
20. A directional display apparatus according to claim 19 , wherein the directional backlight comprises: a waveguide comprising first and second, opposed guide surfaces for guiding input light along the waveguide; and an array of light sources arranged to generate the input light at different input positions in a lateral direction across the waveguide, the waveguide further comprising a reflective end for reflecting input light back through the waveguide, the second guide surface being arranged to deflect light after reflection from the reflective end as output light through the first guide surface, and the waveguide being arranged to direct the output light into optical windows in output directions that are distributed in the lateral direction across the display device in dependence on the input position of the input light.
The directional display system's backlight, which directs light into optical windows, has a waveguide that guides light between two surfaces. An array of light sources injects light at different points along the waveguide's width. A reflective end bounces the light back. The second surface extracts and directs the reflected light through the first surface, creating optical windows. The direction of these windows depends on where the light was initially injected.
21. A directional display apparatus according to claim 20 , wherein the first guide surface is arranged to guide light by total internal reflection and the second guide surface comprises a plurality of light extraction features oriented to direct light guided through the waveguide in directions allowing exit through the first guide surface as the output light and intermediate regions between the light extraction features that are arranged to guide light through the waveguide.
In the directional display system that controls light output based on hand gestures, with a backlight containing a waveguide with light extraction features, the first guide surface uses total internal reflection to guide light. The second surface has light extraction features and intermediate regions. These features redirect the guided light to exit through the first surface. The intermediate regions continue to guide light.
22. A directional display apparatus according to claim 21 , wherein the second guide surface has a stepped shape comprising facets, that are said light extraction features, and the intermediate regions.
The directional display system, which uses a waveguide with light extraction features, features a second guide surface with a stepped shape. The steps act as the light extraction features, alternating with the intermediate regions that guide the light. The facets redirect the light.
23. A directional display apparatus according to claim 21 , wherein the light extraction features have positive optical power in the lateral direction.
In the directional display system with light extraction features, the extraction features (on the second waveguide surface) have positive optical power in the lateral (width) direction. This helps to focus or shape the extracted light, optimizing the viewing angle and brightness.
24. A directional display apparatus according to claim 20 , wherein the first guide surface is arranged to guide light by total internal reflection and the second guide surface is substantially planar and inclined at an angle to direct light in directions that break that total internal reflection for outputting light through the first guide surface, and the display device further comprises a deflection element extending across the first guide surface of the waveguide for deflecting light towards the normal to the first guide surface.
In the directional display system, the first guide surface uses total internal reflection, and the second guide surface is nearly flat but angled to disrupt this reflection. A deflection element on the first surface then redirects the light, directing it towards the viewer.
25. A directional display apparatus according to claim 20 , wherein the reflective end has positive optical power in the lateral direction.
The directional display system has a reflective end with positive optical power. The reflector focuses or shapes the light as it is reflected back through the waveguide, optimizing the directional output.
26. A display apparatus according to claim 19 , being an autostereoscopic display apparatus wherein the control system is further arranged to control the spatial light modulator to display temporally multiplexed left and right images and synchronously to control the directional backlight to direct the output light of the left and right images into respective at least one selected optical windows in positions corresponding to left and right eyes of an observer.
The directional display apparatus described previously, using a directional backlight and spatial light modulator, is an autostereoscopic (3D) display. The controller rapidly switches between left and right eye images on the spatial light modulator. Simultaneously, the backlight steers the left and right images' light to the corresponding eye positions.
27. A directional display apparatus according to claim 13 , further comprising a sensor system arranged to detect the position of the head of the observer, the control system being arranged to change the control of the display device in response to the sensed disposition of the hand of the observer and to the detected position of the head of the observer.
This directional display system, controlled by hand gestures, also uses a head-tracking sensor. The control system adjusts the display's light output (illuminated windows) based on both the hand position and the head position.
28. A display apparatus comprising: a spatial light modulator; a backlight arranged to illuminate the entire area of the spatial light modulator; and a control system arranged to control the transmittance of the spatial light modulator in accordance with input image data to display an image, and further arranged to control the brightness of the backlight, the control system being arranged to operate in at least a first and second mode, wherein in the first mode, the control system is arranged to control the brightness of the backlight to a first brightness level and to control the transmittance of the spatial light modulator in accordance with the input image data with a relationship between the input data and the transmittance of the spatial light modulator that is the same across the image, and in the second mode, the control system is arranged to control the brightness of the backlight to a second brightness level greater than the first brightness level, and to control the transmittance of the spatial light modulator in accordance with the input image data with relationships between the input data and the transmittance of the spatial light modulator that are different in different regions of the image.
A display apparatus includes a spatial light modulator (SLM) and a backlight that illuminates the entire SLM. The controller operates in two modes. In the first mode, the backlight has a first brightness, and the SLM displays an image with a consistent relationship between input data and transmittance. In the second mode, the backlight has a higher brightness, and the SLM displays the image with different relationships between input data and transmittance in different regions of the image.
29. A display apparatus according to claim 28 , wherein in the second mode, a relationship between the input data and the transmittance of the spatial light modulator in at least one highlighted region of the image is the same as the relationship in the first mode.
The display apparatus that switches between display modes with varying backlight brightness and SLM transmittance characteristics, in its second mode, maintains the original data-to-transmittance relationship from the first mode in at least one highlighted region of the image.
30. A display apparatus according to claim 29 , wherein in the second mode, a relationship between the input data and the transmittance of the spatial light modulator in at least one non-highlighted region of the image is scaled to have a peak transmittance that is lower than the peak transmittance of the relationship in the first mode.
The display apparatus that switches between display modes with varying backlight brightness and SLM transmittance characteristics, scales down the data-to-transmittance relationship in at least one non-highlighted region in the second mode, such that the peak transmittance is lower than that of the first mode.
31. A display apparatus according to claim 30 , wherein the peak transmittance of the relationship in the second mode is lower than the peak transmittance of the relationship in the first mode by a factor equal to the ratio of the second brightness level to the first brightness level.
The display apparatus with highlight regions, scales the transmittance of the non-highlighted region by a factor equal to the ratio of the second, higher brightness level, to the first, lower brightness level. This maintains consistent perceived brightness in the non-highlighted regions when the backlight is boosted for the highlighted region.
32. A display apparatus according to claim 28 , wherein the backlight is a directional backlight that is capable of directing output light selectively into optical windows of a set of optical windows in output directions that are distributed across the display apparatus, the control system being arranged to control the backlight to direct output light into at least one selected optical window of the set.
The display apparatus with two brightness modes uses a directional backlight that can direct light to specific optical windows. The control system selects which window(s) to illuminate.
33. A display apparatus according to claim 32 , wherein the backlight comprises: a waveguide comprising first and second, opposed guide surfaces for guiding input light along the waveguide; an array of light sources arranged to generate the input light at different input positions in a lateral direction across the waveguide, the waveguide further comprising a reflective end for reflecting input light back through the waveguide, the second guide surface being arranged to deflect light after reflection from the reflective end as output light through the first guide surface, and the waveguide being arranged to direct the output light into optical windows in output directions that are distributed in the lateral direction across the display apparatus in dependence on the input position of the input light.
The display apparatus with a directional backlight directs light into optical windows and has a backlight including a waveguide. Light enters the waveguide from an array of light sources at different lateral positions. A reflective end bounces light back. The second surface redirects the light through the first surface, creating optical windows whose direction depends on the light source position.
34. A display apparatus according to claim 33 , wherein the first guide surface is arranged to guide light by total internal reflection and the second guide surface comprises a plurality of light extraction features oriented to direct light guided through the waveguide in directions allowing exit through the first guide surface as the output light and intermediate regions between the light extraction features that are arranged to guide light through the waveguide.
In the directional backlight system, the first waveguide surface uses total internal reflection to guide light. The second surface has light extraction features and intermediate regions. These features redirect the guided light to exit through the first surface. The intermediate regions continue to guide light.
35. A display apparatus according to claim 34 , wherein the second guide surface has a stepped shape comprising facets, that are said light extraction features, and the intermediate regions.
The directional backlight system features a second guide surface with a stepped shape. The steps act as the light extraction features, alternating with the intermediate regions that guide the light. The facets redirect the light.
36. A display apparatus according to claim 34 , wherein the light extraction features have positive optical power in the lateral direction.
In the directional backlight system with light extraction features, the extraction features (on the second waveguide surface) have positive optical power in the lateral (width) direction. This helps to focus or shape the extracted light, optimizing the viewing angle and brightness.
37. A display apparatus according to claim 33 , wherein the first guide surface is arranged to guide light by total internal reflection and the second guide surface is substantially planar and inclined at an angle to direct light in directions that break that total internal reflection for outputting light through the first guide surface, and the display apparatus further comprises a deflection element extending across the first guide surface of the waveguide for deflecting light towards the normal to the first guide surface.
In the directional backlight system, the first guide surface uses total internal reflection, and the second guide surface is nearly flat but angled to disrupt this reflection. A deflection element on the first surface then redirects the light, directing it towards the viewer.
38. A display apparatus according to claim 33 , wherein the reflective end has positive optical power in the lateral direction.
The directional backlight system has a reflective end with positive optical power. The reflector focuses or shapes the light as it is reflected back through the waveguide, optimizing the directional output.
39. A display apparatus according to claim 32 , further comprising a sensor system arranged to detect a position of a head of an observer, the control system being arranged to control the display apparatus to direct output light into at least one selected optical window of the set, selected in response to the detected position of the head of the observer.
The display apparatus with a directional backlight that directs light to specific optical windows also incorporates a head-tracking system. The control system selects which optical window to illuminate based on the observer's head position.
40. A display apparatus according to claim 32 , being an autostereoscopic display apparatus wherein the control system is further arranged to control the spatial light modulator to display temporally multiplexed left and right images and synchronously to control the backlight to direct the output light of the left and right images into respective at least one selected optical windows in positions corresponding to left and right eyes of an observer.
This display apparatus, using a directional backlight and spatial light modulator, is an autostereoscopic (3D) display. The controller rapidly switches between left and right eye images on the spatial light modulator. Simultaneously, the backlight steers the left and right images' light to the corresponding eye positions.
41. A method of controlling a display apparatus that comprises a spatial light modulator and a backlight arranged to illuminate the entire area of the spatial light modulator, the method comprising: in a first mode, controlling the brightness of the backlight to a first brightness level and controlling the transmittance of the spatial light modulator in accordance with input image data to display an image with a relationship between the input data and the transmittance of the spatial light modulator that is the same across the image; and in a second mode, controlling the brightness of the backlight to a second brightness level greater than the first brightness level, and controlling the transmittance of the spatial light modulator in accordance with input image data to display an image with relationships between the input data and the transmittance of the spatial light modulator that are different in different regions of the image.
A method controls a display with a spatial light modulator (SLM) and a backlight. In a first mode, the backlight brightness is set to a first level, and the SLM displays an image using a consistent data-to-transmittance relationship. In a second mode, the backlight is brighter, and the SLM displays the image with different data-to-transmittance relationships in different regions.
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October 14, 2014
August 22, 2017
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